Processes for improving thin-film encapsulation

Abstract

A method and apparatus for forming an encapsulation layer on an organic light emitting diode (OLED) patterned substrate are described. A sidewall planarization layer fills voids in a scalloped sidewall of a wall feature on the OLED patterned substrate. The sidewall planarization layer is cured in the same chamber as the deposition of the sidewall planarization layer. A barrier layer is formed on the sidewall planarization layer. The sidewall planarization layer provides a planarized surface for good adhesion of the barrier layer over the sidewall planarization layer which minimizes the possibility of defects to the OLED patterned substrate from moisture of oxygen penetrating the OLED patterned substrate.

1 . A method for forming an encapsulating structure on an organic light emitting diode (OLED) patterned substrate, comprising:
 positioning an OLED patterned substrate into a plasma processing chamber, the OLED patterned substrate having a wall structure with at least one scalloped surface; and   depositing a sidewall planarization layer directly on the wall structure filling at least one of a plurality of voids along the at least one scalloped surface.   
     
     
         2 . The method of  claim 1 , wherein depositing the sidewall planarization layer comprises flowing fluorinated plasma-polymerized hexamethyldisiloxane (pp-HMDSO:F). 
     
     
         3 . The method of clam  1 , further comprising:
 curing the sidewall planarization layer using a mixed gas plasma in the processing chamber.   
     
     
         4 . The method of  claim 1 , further comprising;
 repeating the depositing the sidewall planarization layer.   
     
     
         5 . The method of  claim 4 , further comprising: repeating the curing the sidewall planarization layer. 
     
     
         6 . The method of  claim 1 , wherein the thickness of the sidewall planarization layer is between about 0.1 μm to about 1.0 μm. 
     
     
         7 . The method of  claim 1 , wherein the sidewall planarization layer has a carbon content of greater that 10%. 
     
     
         8 . The method of  claim 2 , wherein the fluorinated plasma-polymerized hexamethyldisiloxane (pp-HMDSO:F) flows through a degasser before entering the plasma processing chamber. 
     
     
         9 . The method  claim 8 , wherein the fluorinated plasma-polymerized hexamethyldisiloxane (pp-HMDSO:F) flows from the degasser and through a vaporizer before entering the processing chamber. 
     
     
         10 . The method of  claim 1 , further comprising forming a barrier layer on the sidewall planarization layer. 
     
     
         11 . A patterned substrate comprising:
 a substrate;   a plurality of organic light emitting diode (OLED) devices formed on a surface of the substrate;   at least one wall structure formed on the surface of the substrate, the wall structure having at least one scalloped surface; and   a sidewall planarization layer disposed over the wall structure and filling at least one of a plurality of voids along the at least one scalloped surface.   
     
     
         12 . The patterned substrate of  claim 11 , wherein the sidewall planarization layer comprises fluorinated plasma-polymerized hexamethyldisiloxane (pp-HMDSO:F). 
     
     
         13 . The patterned substrate of  claim 12 , wherein the sidewall planarization layer has a carbon content of greater than 10%. 
     
     
         14 . The patterned substrate of  claim 11 , wherein the wall planarization layer is deposited directly on the at least one wall structure. 
     
     
         15 . The patterned substrate of  claim 11 , wherein the wall structure is formed from multiple layers of resist material. 
     
     
         16 . The patterned substrate of  claim 15 , wherein the at least one scalloped surface is formed by the multiple layers of the resist material. 
     
     
         17 . The patterned substrate of  claim 11 , wherein the sidewall planarization layer is cured using a mixed gas plasma comprising at least NH 3  and N 2 O. 
     
     
         18 . (canceled) 
     
     
         19 . The patterned substrate of  claim 11 , further comprising a barrier layer formed on the sidewall planarization layer. 
     
     
         20 . A plasma processing chamber for forming an encapsulating structure on an organic light emitting diode (OLED) patterned substrate, the plasma processing chamber comprising:
 a substrate support disposed within a processing region of the plasma processing chamber;   a showerhead disposed within the processing region opposite the substrate support;   a gas source coupled to the showerhead;   an ampoule configured to provide liquid precursors to the chamber; and   a controller configured to control the process for forming an encapsulation structure on the patterned substrate, the process comprising:
 positioning an OLED patterned substrate into the plasma processing chamber, the OLED patterned substrate having a wall structure with at least one scalloped surface; and 
 depositing a sidewall planarization layer directly on the wall structure filling at least one of a plurality of voids along the at least one scalloped surface. 
   
     
     
         21 . The plasm a processing chamber of  claim 20 , wherein the process further comprises forming a barrier layer on the sidewall planarization layer.